As shown in FIG. 1, a previous embodiment of the present invention, tool seat 1 is provided with a specification marking portion 2 on which a specification corresponding to that of a socket 3 is marked. In light of the specification marking portion 2 being a fixed structure, the tool seat 1 is limited in purpose. A socket wrench set may have sockets of up to thirty specifications in the English System, or thirty three specifications in the Metric System. In another words, the tool seat 1 in the prior embodiment is not interchangeable in terms of specification.
As shown in FIG. 2, tool holder base 10 comprises a plurality of seats 12 for holding a plurality of sockets 11 various in specification. The seats 12 are provided with a specification marking portion 14 and are located on the tool holder base 10 by a locating hole 13 of the base 10. The seats 12 are also defective in design in that they are limited in purpose, and that they are not interchangeable in terms of specification.
As shown in FIG. 3, a tool holder base 10 is provided with a plurality of seats for holding a plurality of tool component parts 11. The seats are not interchangeable in terms of specification.